JPH02176261A - Running subtransmission for work truck - Google Patents
Running subtransmission for work truckInfo
- Publication number
- JPH02176261A JPH02176261A JP33367788A JP33367788A JPH02176261A JP H02176261 A JPH02176261 A JP H02176261A JP 33367788 A JP33367788 A JP 33367788A JP 33367788 A JP33367788 A JP 33367788A JP H02176261 A JPH02176261 A JP H02176261A
- Authority
- JP
- Japan
- Prior art keywords
- clutch
- hydraulic piston
- transmission
- pressure
- speed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005540 biological transmission Effects 0.000 claims abstract description 51
- 230000008859 change Effects 0.000 claims abstract description 14
- 230000007246 mechanism Effects 0.000 claims abstract description 11
- 230000003247 decreasing effect Effects 0.000 abstract description 2
- 239000002699 waste material Substances 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 6
- 230000035939 shock Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Landscapes
- Arrangement Or Mounting Of Control Devices For Change-Speed Gearing (AREA)
- Control Of Transmission Device (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、高速状態現出用の第１摩擦クラッチを第１油
圧ピストンによって操作される状態で設け、低速状態現
出用の第２摩擦クラッチを第２油圧ピストンによって操
作される状態で設け、変速操作信号の入力に伴って変速
バルブを自動的に切換え操作する変速制御機構を設けた
作業車の走行用副変速装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a first friction clutch for producing a high-speed state operated by a first hydraulic piston, and a second friction clutch for producing a low-speed state. The present invention relates to an auxiliary transmission for traveling of a work vehicle, which is provided with a clutch operated by a second hydraulic piston, and is provided with a speed change control mechanism that automatically switches and operates a speed change valve in response to input of a speed change operation signal.
上記走行用副変速装置として、走行装置の駆動負荷を検
出するセンサを設け、前記第１油圧ピストンがクラッチ
切り作動開始してからの経過時間を計測するタイマー手
段、このタイマー手段による計測時間が設定時間に達す
ると自動的に前記第２油圧ピストンによるクラッチ入り
作動を開始させると共に、前記走行装置の駆動負荷が増
大するほど大になり、かつ、前記走行装置の駆動負荷が
減少するほど小になるように前記設定時間を前記センサ
からの情報に基いて自動的に変更調節するタイミング調
節手段の夫々を前記変速制御機構に備えたものが、特開
昭６３−９７４３５号公報で開示されている。The auxiliary transmission for traveling is provided with a sensor for detecting the driving load of the traveling device, a timer means for measuring the elapsed time after the first hydraulic piston starts the clutch disengagement operation, and a measurement time by the timer means is set. When the time is reached, the clutch engagement operation by the second hydraulic piston is automatically started, and the larger the driving load of the traveling device increases, and the smaller the driving load of the traveling device decreases. JP-A-63-97435 discloses a shift control mechanism in which each of the shift control mechanisms is provided with timing adjusting means for automatically changing and adjusting the set time based on information from the sensor.
上記従来技術は、走行系に対する負荷に応じて減速側の
摩擦クラッチの入りタイミングを自動変更することで車
速を減じる場合のショックを軽減するようにしたもので
あるが、タイマー手段を利用したタイミング制御を行っ
ているために、変速途中で若干の中立帯が生じ、これが
無駄時間となって変速がやや遅れ気味となることがあり
、ここに改良の余地があった。The above-mentioned conventional technology reduces the shock when reducing vehicle speed by automatically changing the engagement timing of the friction clutch on the deceleration side according to the load on the driving system, but timing control using a timer means As a result, there is a slight neutral zone during gear shifting, which results in wasted time and causes a slight delay in gear shifting, so there was room for improvement.
本発明は、上記無駄時間をほとんど皆無にすることでシ
ョックの少い、かつ、必要以上に間伸びしない円滑迅速
な変速が行えるようにすることを目的とする。An object of the present invention is to eliminate almost all of the above-mentioned wasted time, thereby enabling smooth and quick gear shifting with less shock and no longer than necessary.
上記目的を達成するための本発明特徴構成は、冒記した
作業車の走行用副変速装置において、走行装置の駆動負
荷を検出するセンサ及び前記第１油圧ピストン及び第２
油圧ピストンの作動圧を検出するセンサを設け、前記第
１．第２油圧ピストンのいづれかがクラッチ切り作動を
開始した時点で検出した駆動負荷に対して高速伝動時の
半クラッチ状態をもたらす油圧ピストン作動圧及び低速
伝動時の半クラッチ状態をもたらす油圧ピストン作動圧
を夫々演算し、クラッチ切り作動中の油圧ピストンの作
動圧がクラッチ切り作動前の伝動時に対応する前記半ク
ラッチ現出用の油圧ピストン作動油圧に達すると、クラ
ッチ切り状態にある他方の油圧ピストンによるクラッチ
入り作動を開始し、かつ、このクラッチ入り作動はクラ
ッチ入り後の伝動時に対応する前記半クラッチ現出用の
油圧ピストン作動油圧まで急速に作動油圧の昇圧を行い
、その後、緩速で昇圧してゆく手段を前記変速制御機構
に備えてある点にあり、その作用・効果は次の通りであ
る。The characteristic structure of the present invention for achieving the above object is that, in the above-mentioned sub-transmission device for traveling of a work vehicle, a sensor for detecting the drive load of the traveling device, the first hydraulic piston, and the second hydraulic piston are provided.
A sensor for detecting the operating pressure of the hydraulic piston is provided, and the first. The hydraulic piston working pressure that brings about a half-clutch state during high-speed transmission and the hydraulic piston working pressure that brings about a half-clutch state during low-speed transmission with respect to the drive load detected when one of the second hydraulic pistons starts a clutch disengagement operation. When the operating pressure of the hydraulic piston during clutch disengagement reaches the hydraulic piston operating pressure for half-clutching, which corresponds to the transmission before clutch disengagement, the clutch is activated by the other hydraulic piston in the clutch disengaged state. The clutch engaging operation starts by rapidly increasing the hydraulic pressure to the hydraulic piston hydraulic pressure for half-clutching, which corresponds to the transmission after clutch engagement, and then slowly increasing the hydraulic pressure. The speed change control mechanism is provided with a means for adjusting the speed, and its functions and effects are as follows.
例えば、低速伝動状態から高速伝動状態への切換えの場
合には、高速状態現出用の第１摩擦クラッチに対する第
１油圧ピストンに働く作動油圧と、低速状態現出用の第
２摩擦クラッチに対する第２油圧ピストンに働く作動油
圧は第３図（イ）に示すような特性で制御される。For example, in the case of switching from a low-speed transmission state to a high-speed transmission state, the hydraulic pressure applied to the first hydraulic piston for the first friction clutch for producing a high-speed state, and the hydraulic pressure for the second friction clutch for producing a low-speed state 2 The hydraulic pressure acting on the hydraulic piston is controlled according to the characteristics shown in FIG. 3 (a).
つまり、第２油圧ピストンのクラッチ切り作動に伴って
、その作動油圧（Ｐ、）が所定のクラッチ入り用の作動
圧（Ｐ、）から徐々に低下して低速伝動時の半クラッチ
状態をもたらす値（演算値）（Ｐ２）に達すると、第１
油圧ピストンのクラッチ入り作動のための作動油圧の昇
圧が急速に行われ、高速伝動時の半クラッチ状態をもた
らす値（演算値）（ｐ＋）に達すると、そこから所定の
クラッチ入り用の作動圧まで徐々に昇圧されるのである
。In other words, as the second hydraulic piston disengages the clutch, its working oil pressure (P,) gradually decreases from the predetermined clutch engagement working pressure (P,), resulting in a half-clutch state during low-speed transmission. (calculated value) When reaching (P2), the first
The hydraulic pressure for clutch engagement of the hydraulic piston is rapidly increased, and when it reaches a value (calculated value) (p+) that causes a half-clutch state during high-speed transmission, the hydraulic pressure for clutch engagement is increased from there. The pressure is gradually increased to
又、高速伝動状態から低速伝動状態への切換えの場合に
は、第３図（ロ）に示すような特性で第１、第２油圧ピ
ストンに働く作動圧（Ｐ’ｌ） 、（Ｐａ）が制御され
る。In addition, in the case of switching from a high-speed transmission state to a low-speed transmission state, the working pressures (P'l) and (Pa) acting on the first and second hydraulic pistons have the characteristics shown in Figure 3 (b). controlled.
つまり、本発明によれば、変速直前の走行系の負荷に見
合った半クラッチ伝動状態を介してのみ第１．第２１！
ｊ擦クラッチの切換えを行うので、ショックのない、し
かも無駄時間によって間伸びすることのない迅速な変速
が行えるようになった。In other words, according to the present invention, the first clutch transmission is performed only through the half-clutch transmission state commensurate with the load on the traveling system immediately before the shift. 21st!
Since the friction clutch is switched, it is now possible to quickly shift gears without shock and without delay due to wasted time.
以下、本発明の実施例を図面に基づいて説明する。 Embodiments of the present invention will be described below based on the drawings.
第２図に示すようにエンジン（Ｅ）からの動力を主クラ
ッチ（１）を介して第１筒状軸（２）に伝え、この第１
筒状軸（２）からの動力を油圧式の副変速装置（Ａ）を
介して第２筒状軸（３）に伝え、この第２筒状軸（３）
からの動力をギヤ式の主変速装置（Ｂ）を介して伝動軸
（４）に伝えるよう作業車の走行変速系をミッションケ
ース（Ｍ）に内装する状態で構成する。As shown in Fig. 2, the power from the engine (E) is transmitted to the first cylindrical shaft (2) via the main clutch (1).
The power from the cylindrical shaft (2) is transmitted to the second cylindrical shaft (3) via the hydraulic sub-transmission device (A), and the second cylindrical shaft (3)
The traveling transmission system of the work vehicle is configured to be installed inside the transmission case (M) so that the power from the transmission is transmitted to the transmission shaft (4) via the gear type main transmission (B).
同図に示すように前記副変速装置（Ａ）は、カウンタ軸
（５）、第１筒状軸（２）からの動力をカウンタ軸（５
）を介して第２筒状軸（３）に減速して伝えるための４
つのギヤ（６）・・、第１油圧ピストン（７Ｐ）の入り
作動によって第１、第２筒状軸（２） 、 （３）夫々
を直結状態に設定する高速状態現出用の第１摩擦クラッ
チ（７）、第２油圧ピストン（８Ｐ）の入り作動によっ
て第１筒状軸（２）からの動力を前記４つのギヤ（６）
を介して第２筒状軸に伝える低速状態現出用の第２摩擦
クラッチ（８）で成り、又、前記主変速装置（Ｂ）は、
第２筒状軸（３）に固設した４つのギヤ（９）・・から
の動力を伝動軸（４）に伝えるシンクロメツシュ式の２
つの変速機構（１０） 、 （１０）で成り、伝動軸（
４）には走行装置（図示せず）の駆動負荷を検出するセ
ンサ（ＬＳ）が備えられている。As shown in the figure, the sub-transmission device (A) transfers power from a counter shaft (5) and a first cylindrical shaft (2) to a counter shaft (5).
4 for decelerating and transmitting it to the second cylindrical shaft (3) via )
The first friction for creating a high-speed state that sets the first and second cylindrical shafts (2) and (3) in a direct connection state by the engagement of the two gears (6) and the first hydraulic piston (7P). The clutch (7) and the second hydraulic piston (8P) are engaged to transfer the power from the first cylindrical shaft (2) to the four gears (6).
The main transmission device (B) comprises a second friction clutch (8) for producing a low speed state, which transmits the transmission to the second cylindrical shaft via the main transmission device (B).
A synchronized mesh type 2 that transmits power from four gears (9) fixedly attached to the second cylindrical shaft (3) to the transmission shaft (4).
It consists of two transmission mechanisms (10) and (10), and a transmission shaft (
4) is equipped with a sensor (LS) that detects the driving load of the traveling device (not shown).
因みに、第１．第２筒状軸（２） 、 （３）に内嵌す
る軸（１１）は外部動力取出し用のものである。By the way, No. 1. The shaft (11) fitted inside the second cylindrical shafts (2) and (3) is for extracting external power.
当該作業車では前記副変速装置（Ａ）を切換える際のシ
ョックの低減を図るため第１．第２摩擦クラッチ（７）
、 （８）の作動を次のようにして制御している。In this work vehicle, in order to reduce the shock when switching the auxiliary transmission (A), the first. Second friction clutch (7)
, (8) are controlled as follows.
即ち、第１図に示すように、副変速装置（Ａ）を切換操
作する変速手段（１２）が操作レバー（１２ａ）と、こ
れと連係する切換スイッチ（１２ｂ）とで成り、この変
速手段（１２）及び前記負荷センサ（ＬＳ）からの信号
が入力すると共に、前記第１．第２油圧ピストン（７Ｐ
） 、 （８Ｐ）を電磁式の２つの変速バルブ（１３）
、 （１３）を介して操作する変速操作機構（１４）
を設け、この変速操作機構（１４）に対して第１油圧ピ
ストン（７Ｐ）及び第２油圧ピストン（８Ｐ）の作動油
圧を検出するセンサ（ｐｓ＋Ｌ （ｐｓｚ）と、前記負
荷センサ（ＬＳ）からの検出結果及び副変速装置（Ａ）
及び主変速装置（Ｂ）のギヤ伝動比に基づいて、その検
出負荷に対する高速伝動時の半クラッチ状態にもたらす
第１油圧ピストン（７Ｐ）の作動油圧（Ｐ１）、前記検
出負荷に対する低速伝動時の半クラ・７チをもたらす第
２油圧ピストン（８Ｐ）の作動油圧（Ｐ２）を演算する
演算手段（１５）とを備えて、副変速装置（Ａ）の制御
系が構成されている。That is, as shown in FIG. 1, the transmission means (12) for switching the auxiliary transmission (A) is composed of an operating lever (12a) and a changeover switch (12b) linked thereto. 12) and the load sensor (LS) are input, and the first. 2nd hydraulic piston (7P
), (8P) are two electromagnetic variable speed valves (13)
, (13) a speed change operation mechanism (14) operated through the
A sensor (ps+L (psz)) for detecting the working oil pressure of the first hydraulic piston (7P) and the second hydraulic piston (8P), and a sensor (ps+L (psz)) for detecting the working oil pressure of the first hydraulic piston (7P) and the second hydraulic piston (8P), and a Detection results and auxiliary transmission (A)
Based on the gear transmission ratio of the main transmission (B), the working oil pressure (P1) of the first hydraulic piston (7P) brought to a half-clutch state during high-speed transmission with respect to the detected load, and the working pressure (P1) of the first hydraulic piston (7P) during low-speed transmission with respect to the detected load. A control system of the auxiliary transmission (A) is configured to include a calculation means (15) for calculating the working oil pressure (P2) of the second hydraulic piston (8P) that brings about half-clutch/7-ch.
次に、上記変速制御機構（１４）の作動について説明す
る。Next, the operation of the speed change control mechanism (14) will be explained.
副変速装置（Ａ）が低速から高速に切換えられる場合、
第３図（イ）に示すように、変速切換え時点（ｔｌ）か
ら第２油圧ピストン（８Ｐ）の作動圧（Ｐ、）は所定の
クラッチ入り用圧（Ｐｏ）から漸次低下する。前記時点
（１，）において、その時点でセンサ（ＬＳ）によって
検出された負荷に基づいて、半クラッチ伝動状態をもた
らす前記作動油圧（Ｐｌ）及び（Ｐｚ）が演算記憶され
る。When the auxiliary transmission (A) is switched from low speed to high speed,
As shown in FIG. 3(a), the operating pressure (P, ) of the second hydraulic piston (8P) gradually decreases from the predetermined clutch engagement pressure (Po) from the time of gear changeover (tl). At the time point (1,), the working oil pressure (Pl) and (Pz) that bring about the half-clutch transmission state are calculated and stored based on the load detected by the sensor (LS) at that time point.
そして、第２油圧ピストン（８Ｐ）の作動圧（ｐ１）、
（ＰＳ２）が半クラッチ現出用の作動圧（Ｐ２）にまで
低下した時点（ｔよ）から第１油圧ピストン（７Ｐ）の
作動圧（Ｐ７）の急速な上昇制御がなされ、第１油圧ピ
ストン（７Ｐ）の作動圧（Ｐ、）が半クラッチ現出用の
前記作動圧（ｐ＋）に達すると、以後は緩速の昇圧が所
定のクラッチ入り用圧（Ｐｏ）まで続く。And the working pressure (p1) of the second hydraulic piston (8P),
From the time (t) when the pressure (PS2) has decreased to the working pressure (P2) for half-clutching, the working pressure (P7) of the first hydraulic piston (7P) is controlled to increase rapidly, and the first hydraulic piston When the operating pressure (P, ) of (7P) reaches the operating pressure (p+) for half-clutching, the pressure increases slowly until the predetermined clutch engagement pressure (Po) is reached.
又、高速から低速への切換え時にも第３図（ロ）に示す
ように、変速開始時点（１＋）における検出負荷に基づ
いて得られる半クラッチ現出用作動圧（ｐ＋）、 （ｐ
１）、（ＰＳ２）への到達タイミングでピストン作動圧
の昇圧制御が同様に行われる。Also, when switching from high speed to low speed, as shown in Figure 3 (b), the operating pressure for half-clutch appearance (p+), (p
1) and (PS2), pressure increase control of the piston operating pressure is similarly performed.
以上のように昇圧制御することで、変速途中で伝動中立
状態がもたらされるのを回避することができるのである
。By performing the pressure increase control as described above, it is possible to avoid a transmission neutral state occurring during a gear shift.
因みに、前記伝動軸（４）に設けた負荷センサ（Ｓ）は
第１図及び第４図に示すように、伝動軸（４）に貼付し
た磁歪性棒片（１６）・・と、この磁歪性棒片（１６）
・・に対して磁界を与える界磁コイル（１７）と、伝動
軸（４）の涙れに起因する磁歪性棒片（１６）の磁歪現
象を取出す検出コイル（１８）と、界磁コイル（１７）
に交流信号を印加し、かつ、検出コイル（１８）からの
信号を平滑してトルク変動を電圧変化に変換する制御部
（１９）とで成っている。Incidentally, as shown in FIGS. 1 and 4, the load sensor (S) installed on the transmission shaft (4) is connected to a magnetostrictive rod (16) attached to the transmission shaft (4). Sex stick piece (16)
A field coil (17) that applies a magnetic field to ..., a detection coil (18) that detects the magnetostrictive phenomenon of the magnetostrictive rod (16) caused by tearing of the transmission shaft (4), and a field coil ( 17)
The control section (19) applies an alternating current signal to the detection coil (18) and smoothes the signal from the detection coil (18) to convert torque fluctuations into voltage changes.
更に、両コイル（１７） 、 （１８）はボビン（２０
）に巻回して形成されると共に、ヘアリング（２１）
、 （２１）を介して伝動軸（４）に対して外嵌され、
かつ、このボビン（２０）に取付けたギヤ（２２）に対
して、ミッションケース（Ｍ）の側壁に突設した保合片
（２３）を係合させて該ボビン（２０）の回り止めが為
されている。Furthermore, both coils (17) and (18) are attached to the bobbin (20
) and a hair ring (21)
, externally fitted onto the transmission shaft (4) via (21),
In addition, the gear (22) attached to the bobbin (20) is engaged with a retaining piece (23) protruding from the side wall of the transmission case (M) to prevent the bobbin (20) from rotating. has been done.
尚、特許請求の箱間の項に図面との対照を便利にする為
に符号を記すが、該記入により本発明は添付図面の構造
に限定されるものではない。Incidentally, although reference numerals are written in the terms between the boxes of the patent claims for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.
図面は本発明に係る作業車の走行用副変速装置の実施例
を示し、第１図は該変速装置の操作系を示すブロック図
、第２図はミッションケースの断面図、第３図Ｃイ）、
（ロ）は低速から高速、および高速から低速への切換え
時の油圧ピストンの作動圧力変化を示すグラフ、第４図
はセンサの構造を示す断面図である。
（７）・・・・・・第１摩擦クラッチ、（７Ｐ）・・・
・・・第１油圧ピストン、（８）・・・・・・第２摩擦
クラッチ、（８Ｐ）・・・・・・第２油圧ピストン、（
１３）・・・・・・変速パルプ、（１４）・・・・・・
変速制御機構、（ＬＳ）・・・・・・負荷検出用のセン
サ、（ｐｓ 、 ） 、 （ｐｓ ２）・・・・・・作
動圧検出用のセンサ、（ＰＩ）、 （ｐｉ）・・・・・
・半クラッチ現出用の作動圧、（ｐ２） 、 （ｐｅ）
・・・・・・油圧ピストンの作動圧。The drawings show an embodiment of the auxiliary transmission for traveling of a working vehicle according to the present invention, FIG. 1 is a block diagram showing the operation system of the transmission, FIG. 2 is a sectional view of the transmission case, and FIG. ),
(B) is a graph showing changes in the operating pressure of the hydraulic piston when switching from low speed to high speed and from high speed to low speed, and FIG. 4 is a sectional view showing the structure of the sensor. (7)...First friction clutch, (7P)...
...First hydraulic piston, (8)...Second friction clutch, (8P)...Second hydraulic piston, (
13)... Variable speed pulp, (14)...
Shift control mechanism, (LS)...Sensor for load detection, (ps, ), (ps2)...Sensor for operating pressure detection, (PI), (pi)... ...
・Operating pressure for half-clutch appearance, (p2), (pe)
・・・・・・Operating pressure of hydraulic piston.
Claims (1)
ストン（７Ｐ）によって操作される状態で設け、低速状
態現出用の第２摩擦クラッチ（８）を第２油圧ピストン
（８Ｐ）によって操作される状態で設け、変速操作信号
の入力に伴って変速バルブ（１３）を自動的に切換え操
作する変速制御機構（１４）を設けた作業車の走行用副
変速装置であって、走行装置の駆動負荷を検出するセン
サ（ＬＳ）及び前記第１油圧ピストン（７Ｐ）及び第２
油圧ピストン（８Ｐ）の作動圧（Ｐ＿７）、（Ｐ＿８）
を検出するセンサ（ＰＳ＿１）、（ＰＳ＿２）を設け、
前記第１、第２油圧ピストン（７Ｐ）、（８Ｐ）のいづ
れかがクラッチ切り作動を開始した時点で検出した駆動
負荷に対して高速伝動時の半クラッチ状態をもたらす油
圧ピストン作動圧（Ｐ＿１）、及び低速伝動時の半クラ
ッチ状態をもたらす油圧ピストン作動圧（Ｐ＿２）を夫
々演算し、クラッチ切り作動中の油圧ピストンの作動圧
がクラッチ切り作動前の伝動時に対応する前記半クラッ
チ現出用の油圧ピストン作動油圧に達すると、クラッチ
切り状態にある他方の油圧ピストンによるクラッチ入り
作動を開始し、かつ、このクラッチ入り作動はクラッチ
入り後の伝動時に対応する前記半クラッチ現出用の油圧
ピストン作動油圧まで急速に作動油圧の昇圧を行い、そ
の後、緩速で昇圧してゆく手段を前記変速制御機構（１
４）に備えてある作業車の走行用副変速装置。A first friction clutch (7) for producing a high-speed state is provided to be operated by a first hydraulic piston (7P), and a second friction clutch (8) for producing a low-speed state is provided by a second hydraulic piston (8P). A sub-transmission device for traveling of a work vehicle, which is provided with a speed change control mechanism (14) that is operated by a speed change valve (13) and automatically switches and operates a speed change valve (13) in accordance with the input of a speed change operation signal. A sensor (LS) that detects the driving load of the device, the first hydraulic piston (7P), and the second
Working pressure of hydraulic piston (8P) (P_7), (P_8)
Provide sensors (PS_1) and (PS_2) that detect
a hydraulic piston operating pressure (P_1) that brings about a half-clutch state during high-speed transmission with respect to the drive load detected at the time when either the first or second hydraulic piston (7P) or (8P) starts a clutch disengagement operation; and the hydraulic piston working pressure (P_2) that brings about a half-clutch state during low-speed transmission, and the working pressure of the hydraulic piston during clutch disengagement is determined to be the hydraulic pressure for half-clutch state corresponding to the time of transmission before clutch disengagement. When the piston operating oil pressure is reached, the other hydraulic piston that is in the clutch disengaged state starts clutch engagement operation, and this clutch engagement operation is performed using the hydraulic piston operating oil pressure for half-clutching, which corresponds to the transmission after clutch engagement. The speed change control mechanism (1
4) A sub-transmission device for traveling of a work vehicle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33367788A JPH02176261A (en) | 1988-12-28 | 1988-12-28 | Running subtransmission for work truck |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33367788A JPH02176261A (en) | 1988-12-28 | 1988-12-28 | Running subtransmission for work truck |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02176261A true JPH02176261A (en) | 1990-07-09 |
Family
ID=18268735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33367788A Pending JPH02176261A (en) | 1988-12-28 | 1988-12-28 | Running subtransmission for work truck |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02176261A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000032960A1 (en) * | 1998-12-03 | 2000-06-08 | Hitachi, Ltd. | Gear type automatic transmission and car using the gear type automatic transmission |
-
1988
- 1988-12-28 JP JP33367788A patent/JPH02176261A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000032960A1 (en) * | 1998-12-03 | 2000-06-08 | Hitachi, Ltd. | Gear type automatic transmission and car using the gear type automatic transmission |
| US6679133B1 (en) | 1998-12-03 | 2004-01-20 | Hitachi, Ltd. | Gear-type automatic transmission and car using the gear type automatic transmission |
| US6889570B2 (en) | 1998-12-03 | 2005-05-10 | Hitachi, Ltd. | Gear-type automatic transmission and an automobile using the gear-type automatic transmission |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3590939B2 (en) | Transmission control apparatus and method based on detection of drive system torque | |
| JP2002013634A (en) | Shift-assisting device for transmission | |
| JP2001235028A (en) | Shift assist device for transmission | |
| JPH03292446A (en) | Shift operating hydraulic pressure controller for automatic transmission | |
| JPH085396Y2 (en) | Clutch control device | |
| JPH0356719A (en) | Clutch controller | |
| JPH02176261A (en) | Running subtransmission for work truck | |
| JPH0989090A (en) | Synchronization control device for vehicle | |
| JPH06346952A (en) | Power transmission controller | |
| JP2006153235A (en) | Automatic gear change control device of synchronous meshing transmission gear | |
| JPS62278366A (en) | Speed control system for hydraulic pressure driven vehicle provided with gear type transmission | |
| GB2356433A (en) | Automatic transmission with automatic shift-down apparatus | |
| JPS6397435A (en) | Sub-transmission device for traveling of working vehicle | |
| JPH0587712B2 (en) | ||
| JPH0466733B2 (en) | ||
| JP2003336734A (en) | Control device and control method for automatic transmission | |
| JPS62200037A (en) | Controller for hydraulic clutch | |
| JPS62113952A (en) | Shifting method and device for automatic transmission for vehicle | |
| JPH07113406B2 (en) | Control device for compound clutch type multi-stage gear transmission | |
| JPH04185541A (en) | Overload reduction system | |
| JPS6011763A (en) | Start-shift selecting control system for automatic clutch | |
| JPH026235A (en) | Automatic change gear | |
| JPH02113167A (en) | Transmission for running vehicle | |
| JPH02248725A (en) | Automatic clutch control device | |
| JPS63167156A (en) | Control device for electronic control transmission |